Hi all, i have a trouble with sabayon 4.2 gnome and backlight on my laptop Samsung R560.I was looking on google why i can't change my backlight and i found something about ACPI, but i don't know how to ON ACPI MODE in Sabayon.When i power on my laptop everything is fine, in grub i can change my backlight putting FN+Left Arrow or FN+Right Arrow, but after Starting loading Sabayon this shortcut's won't work. I can't change backlight using gnome applet, when it is 100% it looks nice, but when i change this i always have an error "can not get laptop lcd brightness". Tell me which logs i should put here, and how to make my laptop additional function work.

Open up /boot/grub/grub.conf as root and find the kernel line. It will start with "kernel /boot/" and some other stuff. You should try adding noapic (notice, it's not noacpi) to the end of the line. If you are using gedit to modify this file, you'll need to maximize the window because gedit will wrap a long line into multiple lines. Then restart and see if it works. If it doesn't, then replace the noapic part with acpi=off and restart. It should work with either noapic or acpi=off, but in the event that it doesn't, you can try putting both in. It doesn't matter what order.

# grub.conf generated by the Sabayon Linux Installer## Note that you do not have to rerun grub after making changes to this file# NOTICE: You have a /boot partition. This means that# all kernel and initrd paths are relative to /boot/, eg.# root (hd0,6)# kernel /kernel-genkernel real_root=/dev/VolGroup00/LogVol00# initrd /initramfs-genkernel### AUTOMAGIC BOOT DEVICE DETECTION -- DO NOT REMOVE ####boot=sda### AUTOMAGIC BOOT DEVICE DETECTION END ###default=2timeout=5splashimage=(hd0,6)/grub/splash.xpm.gz

I'd be willing to bet that it's a HAL issue. I used to have problems with the backlight on my Dell Inspiron 9300 when I was running Gentoo on an older non-evdev non-Hal version of Xorg. Now it works great because Dell supplied to the freedesktop.org team help in developing a .fdi file for it's notebooks that correspond to the special/extra keys that Dell uses for controlling the backlight, volume level, turning on and off the wifi/bluetooth, etc.

I suspect that since Samsung isn't nearly as large a company or has nearly the installed base, that the necessary .fdi file doesn't exist for your notebook. The first thing to try is to go to Samsung's website to see what kind of Linux support they provide. If you're lucky they've got something there that can help.

If they don't there's a work around. If you go to /usr/share/hal/fdi folder you can poke around and look at the .fdi files for the Dell, Sony, Mac, and Levono notebooks with a text editor. Copy the file that has controls as close to yours as possible into your home directory so it can be edited. Change the key combination to suit your purpose, remove the key combos that don't apply. Be careful with formatting and syntax this must stay the same.

Once you've got it adjusted, rename it to something like "10-samsung-panel.fdi" (without "") and place it in your /etc/hal/fdi/policy/ folder. Time to test. If you made the right adjustments all you have to do is log out of X and restart HAL and you should be good to go.